Background: I have six hens that are 4 years old or older, established flock. Recently I bought six pullets, approx. 6 months old. They are about the same size as the grown hens. I put the six new girls in a chicken tractor for quarantine. Within a few days, one was showing respiratory symptoms so I separated her for observation. By evening she was rattling, albeit bright and no discharge or bubbles or stinky stuff. I gave her to a friend who was perfectly happy to treat her, and keep her. A few days later the buff orphinton looked under the weather. It was really cold, and at first I just thought she was just cold-- sorta puffed up. So I separated her, and "thought about things". She was showing mild respiratory symptoms- noisy breathing and a random sneeze. I ended up treating her and she rebounded like a champ. Of the remaining 4, one sexlink and the EE looked a little bit under the weather, but not bad enough to bring in. All rebounded. Since I gave one away, I now have 5 pullets, and they are eating, drinking, chickening, and doing great. They've started to lay eggs. I realize that since 3 of my remaining 5 pullets showed some signs of stress/sickness, that they could relapse under stress. None were at death's door and they might have recovered on their own, I don't know. THE QUESTION: Now how do I integrate the two groups-- in terms of this respiratory thing? How long do I wait? Any special considerations? I'm somewhat anxious to move all to the big coop, since it's such a better situation that the little quarantine tractor. Thanks in advance for guidance, advise. The last time I added new hens it was a group of 3 mature hens, to my younger non aggressive pullets. It went pretty well-- but there was no hint of illness for any of them.